author = { Fraser, Scott C. AND Diener, Edward AND Beaman, Arthur L. AND Kelem, Roger T. },

title = { Two, three, or four heads are better than one: Modification of college performance by peer monitoring. },

publisher = {American Psychological Association (APA)},

isbn = {1939-2176},

isbn = {0022-0663},

year = {1977},

url = { http://slubdd.de/katalog?TN_libero_mab2 }